Herbicidal compositions

ABSTRACT

A herbicidal composition comprising a sulfonylurea derivative of formula (I) ##STR1## wherein Q is --CH═CH-- or --S--, R is straight or branched C1-3 alkyl, and X is --OCH 3  or --CH 3 , or an agriculturally acceptable salt thereof, and at least one co-herbicide selected from: urea herbicides, imidazolinone herbicides, diphenyl ether herbicides, hydroxybenzonitrile herbicides, 2-(4-aryloxyphenoxy) alkanoic acid herbicides and oxime herbicides, carbamate and thiocarbamate herbicides, quaternary ammonium salt herbicides, triazole herbicides, phytohormone herbicides, including aryloxyalkanoic acid herbicides, arenecarboxylic acid herbicides, pyridinecarboxylic acid herbicides, and pyridyloxyacetic acid herbicides, 2,6-dinitroaniline herbicides, amide herbicides, and anilide herbicides, the respective herbicidal constituents being present in amounts such that the compositions display selectivity of herbicidal action with respect to crops being treated pre- or post-emergent and exhibit synergistic effects when applied at herbicidally effective rates.

This application is a 371 of PCT/IB95/01059, filed on Nov. 27, 1995.

This invention relates to herbicidal compositions comprising aherbicidal sulfonylurea derivative and at least one co-herbicideselected from a range of co-herbicides. It further relates to the use ofthe aforesaid herbicidal compositions for controlling undesiredvegetation in crops, especially cereal crops.

EP-A-0 477 808 discloses sulfonylurea derivatives of the general formula(I) ##STR2## wherein Q is --CH═CH-- or --S--, R is straight or branchedC1-3 alkyl, and X is --OCH₃ or CH₃, or an agriculturally acceptable saltthereof. Examples of agriculturally acceptable salts include salts withinorganic bases such as alkali metal (e.g. sodium, potassium, etc.),alkali earth metal (e.g. magnesium, calcium, etc.) and ammonia as wellas organic bases such as dimethylamine, triethylamine, pyrrolidine,piperidine, piperazine, morpholine, benzylamine, ethanolamine, anddiethanolamine. The said herbicidal sulfonylurea derivatives are said topresent advantageous activity against broadleaf weeds and graminaceousweeds without adverse effects on valuable small grain cereal cropparticularly wheat.

The aforesaid sulfonylurea derivatives do not readily control all theweed species encountered in small grain cereal crops in practice. Moreparticularly weeds such as, for example:

Alopecurus myosuroides (black grass)

Avena fatua (wild oats)

Galium aparine (bedstraw cleavers)

Lamium purpureum (red dead nettle)

Matricaria chamomilla (mayweed)

Stellaria media (common chickweed)

Veronica persica (common field speedwell)

are not easily controlled by said derivatives unless relatively highrates are used. These high rates may then be detrimental to the cropsand, of course, reduce the commercial value of the sulfonylureaderivatives. Moreover, environmental considerations increasingly requirethat lower amounts of herbicidally active substances be used in thecontrol of undesired vegetation.

It is known to overcome this type of problem to some extent by the useof herbicidal compositions in which more than one type herbicide ispresent. Such compositions, however, should preferably still show theadvantageous properties of the individual herbicide constituents anddisplay a synergistic effect between them, whilst maintainingselectivity of herbicidal action with respect to the crop. It is,nonetheless, difficult to determine appropriate combinations ofherbicides in view of the considerable number of different types ofherbicides available and the plurality of individual herbicides withineach such type.

The purpose of the present invention is to provide herbicidalcompositions comprising a sulfonylurea derivative as defined above andat least one co-herbicide, said compositions having a broader spectrumof weed control than each individual herbicide constituent, whilstretaining the selectivity of herbicidal action of the sulfonylureaderivative constituent.

A further purpose of the present invention is to provide herbicidalcompositions which, when applied pre-emergent or post-emergent, displayan enhanced and broader spectrum of herbicidal activity than thesulfonyl urea derivatives used alone, whilst retaining the selectivityof action of the herbicidal action of the sulfonylurea derivativesdefined above with regard to the crops being treated.

A further purpose of the present invention is to provide a method ofcontrolling the germination and growth of undesired vegetation in aselective manner with regard to crops, e.g. cereal crops, being treated,which comprises applying to the crop, pre- or post-emergent, acomposition according to the present invention.

It is surprising that the compositions of the present inventioncomprising a sulfonylurea herbicide as defined and at least oneco-herbicide are particularly efficient in combating a broad spectrum ofweeds while still displaying a selectivity of action with respect to thecrops. It is further surprising that the compositions of the presentinvention additionally exhibit synergistic effects.

According to the present invention there are provided herbicidalcompositions comprising a sulfonylurea derivative of formula (I) asdefined above and at least one co-herbicide selected from:

urea herbicides,

imidazolinone herbicides,

diphenyl ether herbicides,

hydroxybenzonitrile herbicides,

2-(4-aryloxyphenoxy) alkanoic acid herbicides and oxime herbicides,

carbamate and thiocarbamate herbicides,

quaternary ammonium salt herbicides,

triazole herbicides,

phytohormone herbicides, including aryloxyalkanoic acid herbicides,arenecarboxylic acid herbicides, pyridinecarboxylic acid herbicides, and

pyridyloxyacetic acid herbicides,

2,6-dinitroaniline herbicides,

amide herbicides, and

anilide herbicides,

in amounts such that the compositions display selectivity of herbicidalaction with respect to crops being treated pre- or post-emergent andexhibit synergistic effects when applied at herbicidally effectiverates.

Thus, the ratio of the sulfonylurea herbicide to the co-herbicide is, asappropriate, i.e. depending upon the specific herbicides present in thecomposition according to the invention, from about 1:1 to about 1:150and the amounts applied are in the ratio of from about 10:30 g/ha toabout 25:1500 g/ha.

The above classification of co-herbicides is based upon theclassification of herbicides used in "The Pesticide Manual", ninthedition, published in 1991 by the British Crop Protection Council.

It has been found that the compositions according to the presentinvention show improved herbicidal efficacy with respect to thesulfonylurea derivative (I) constituent on its own since they do notpresent the same weaknesses on weed species which are difficult tocontrol by the use of the sulfonylurea derivative alone. Moreover, therange of weeds on which the compositions of the present invention areherbicidally effective is broadened when compared to the use of therespective sulfonylurea herbicide on its own.

Furthermore, the beneficial selectivity of action of the sulfonylureaherbicide constituent with regard to cereals (including, but not limitedto, wheat, barley, oats and rye), is not adversely affected.

It is further surprising that the compositions according to the presentinvention do not simply present an additive herbicidal effect againstmost of the weeds encountered in monocotyledonous crops, but show asynergistic effect.

As a consequence, the amounts of the individual herbicidally activeconstituents in the compositions of the present invention which requireto be applied to crops can be reduced over the quantities required whenthey are used alone, whilst maintaining the efficacy of the herbicidalaction at the same level. In addition, the compositions even show anacceptable level of activity against weeds where each of the herbicidesused individually would be inefficient on its own because the amountused would be too low, thus permitting an increase in the safety marginfor sub-optimal applications.

Preferred sulfonylurea derivatives are those according to formula Iabove in which --R is --C₂ H₅, --X is --OCH₃, and Q is --CH═CH-- or--S--, i.e. compounds A and B (see Example 1).

Preferred urea herbicides include isoproturon, chlortoluron, metoxuron,linuron, monolinuron, dimefuron and diuron. Isoproturon is particularlypreferred.

Preferred imidazolinone herbicides include imazamethabenz-methyl,imazapyr, imazaquin, and imazapyr ammonium. Imazamethabenz-methyl("ASSERT"--trade mark) is particularly preferred.

Preferred diphenyl ether herbicides include bifenox, acifluorfen,fluoroglycofen ethyl, fomesafen, lactofen, and oxyfluorfen. Bifenox isparticularly preferred.

Preferred hydroxybenzonitrile herbicides include bromoxynil and ioxynil.Bromoxynil is particularly preferred.

Preferred 2-(4-aryloxyphenoxy) alkanoic acid herbicides includefenoxaprop ethyl, fenoxaprop-P-ethyl ("PUMA"--trademark), fluazifop-P,fluazifop-butyl, haloxyfop-methyl, haloxyfop-etotyl, isoxapyrifop,propaquizafop-ethyl, quizalofop-ethyl, quizalofop-P-ethyl, anddiclofop-methyl.

Preferred carbamate/thiocarbamate herbicides include tri-allate,di-allate, barban, dimepiperate, molinate, and thiobencarb. Tri-allateis particularly preferred.

A particularly preferred quaternary ammonium salt herbicide isdifenzoquat metilsulfate.

A preferred triazole derivative has the following formula (II) ##STR3##wherein R is a straight-chain alkyl group having 1 to 10 carbon atomswhich is non-substituted or substituted with 1 to 19 fluorine atoms, abranched alkyl group having 3 to 10 carbon atoms which isnon-substituted or substituted with 1 to 19 fluorine atoms, a cyclicalkyl group having 3 to 10 carbon atoms, an alkyl group having 1 to 3carbon atoms which is substituted with an alicyclic structure having 3to 7 carbon atoms, a phenyl group or an aralkyl group having 7 to 9carbon atoms:; X¹ is a halogen or an alkyl group having 1 to 3 carbonatoms; X² is a hydrogen, a halogen or an alkyl group having 1 to 3carbon atoms; Y¹ is a hydrogen or a fluorine; and Y² is a hydrogen or afluorine, more preferably where X¹ is chlorine, X² is hydrogen, Y¹ andY² are hydrogen and R means --CH₂ CF₂ CF₃. It is known to showpre-emergent and post-emergent herbicidal activity. Another preferredtriazole herbicide is amitrole.

A particularly preferred triazole herbicide is flupoxam. This compoundcorresponds to formula II above in which Y¹ and Y² are hydrogen, X¹ ischlorine, X² is hydrogen and R is --CH₂ CF₂ CF₃.

Preferred phytohormone herbicides include the aryloxyalkanoic acidherbicides 2,4-D, 2,4 DB, MCPA, MPCB, PCPB, MCPP (known as CMPP andmecoprop), mecoprop-P, dichlorprop, dichlorprop-P, and clomeprop, thearenecarboxylic herbicide dicamba, the pyridinecarboxylic acid herbicidepicloram, the pyridyloxyacetic acid herbicides fluroxypyr,triclopyr-butotyl, and triclopyr-triethylammonium. Of the foregoing MCPPand fluroxypyr are particularly preferred.

Preferred 2,6-dinitroaniline herbicides include pendimethalin,trifluralin, fluazinam, benfluralin, butralin and fluchloralin.Pendimethalin is particularly preferred.

Preferred oxime herbicides include tralkoxydim, sethoxydim, alloxydimand clethodim.

Preferred amide herbicides include isoxaben, tebutam, and propyzamide.Isoxaben is particularly preferred.

Preferred anilide herbicides include diflufenican, mefenacet andmonalide. Diflufenican is particularly preferred.

In a yet further aspect, the present invention provides herbicidalcompositions as defined above comprising a sulphonylurea derivative anda mixture of two or more of the above listed co-herbicides.

The compositions according to the invention may contain the sulfonylureaderivative and the co-herbicide in a wide range of ratios, depending onthe particular conditions of application, the crop being treated, theweeds being combated and the type of herbicides being used in thecompositions.

According to another embodiment of the present invention, advantageouscombinations may comprise the sulfonylurea derivative (I) disclosedabove and a mixture of two or more of the above-cited co-herbicides.

In a further aspect the present invention provides a process forselectively controlling the growth or germination of undesired plantscomprising applying sequentially or simultaneously, pre- orpost-emergent to the plants, to the seeds thereof, or to the locus ofthe seed or plants or seeds, the herbicidally active constituents of acomposition according to the invention.

Thus it is to be understood that the present invention includes theapplication of the individual herbicidal constituents of thecompositions of the present invention simultaneously or sequentially tothe seed, plant or locus of the seed or plant. A simultaneousapplication is preferred. In this latter case, the composition may beapplied:

(a) in the form of a tank mix of the individual herbicidal constituents,if desired complemented by the incorporation of agriculturally knownadjuvants, such as cariers, diluents, surfactants, anti-freeze agents,and the like;

(b) in the form of a finely-divided powdered mixture of the sulfonylureaderivative and the co-herbicide;

(c) in the form of a ready-to-use formulated composition comprising theherbicidal components as defined complemented by formulation aids,surfactants, etc; or

(d) in the form of a solution, dispersion or emulsion of a moreconcentrated, or even solid, formulated product which again comprisesthe herbicidal constituents, formulation aids and other agriculturallyknown adjuvants.

The application rates of the compositions of the invention depend uponthe particular conditions of use and on the particular herbicidalcomposition being applied.

Herbicidal compositions containing the sulfonylurea derivative and theco-herbicide as well as formulations derived thereof, includingconcentrates of aqueous or non-aqueous solutions and of aqueoussuspensions which require dilution prior to application, are allembodiments of the present invention and are all referred to hereafterby the term compositions. The compositions may contain the herbicidallyactive components mixture in a range from 0.1% to 100% weight and mayalso contain at least one agriculturally acceptable adjuvant in liquidor solid form. In the compositions the herbicidal components may bepresent in free form or in the form of an agriculturally acceptable acidaddition salt, complex or association product, such as for example acomplex or association product formed with metal ions.

The compositions are prepared by known techniques by ad-mixing theherbicidally active ingredients with one or more adjuvants, includingdiluents, extenders, carriers and conditioning agents, to providecompositions in the form of finely divided particulate solids, granules,pellets, solutions, dispersions or emulsions. Thus the activeingredients can be used with an adjuvant such as a finely divided solid,a liquid of organic origin, water, a surfactant, a dispersing agent, anemulsifying agent, a stabilising agent, an anti-freeze agent, ananti-foam agent or any suitable combination of these.

Suitable solvents include water, alcohols (e.g. methanol, ethanol,n-propanol, isopropanol, ethylene glycol, etc.), ketones (e.g. acetone,methyl ethyl ketone, etc.) ethers (e.g. dioxane, tetrahydrofuran,ethylene glycol monomethyl ether, diethylene glycol monomethyl ether,propylene glycol monomethyl ether, etc.), aliphatic hydrocarbons (e.g.kerosene, lamp oil, fuel oil, machine oil, etc.), aromatic hydrocarbons(e.g. benzene, toluene, xylene, solvent naphta, methylnaphthalene, etc.)halogenated hydrocarbons (e.g. dichloromethane, chloroform, carbontetrachloride, etc.), acid amides (e.g. dimethylformamide,dimethylacetamide, etc.), esters (e.g. ethyl acetate, butyl acetate,fatty acid glycerol ester, etc.) and nitriles (e.g. acetonitrile,propionitrile, etc.). These solvents may be used individually or in asuitable mixed form of two or more ingredients in a suitable ratio.

Examples of the solid carrier (diluent/extender) include vegetablepowders (e.g. soybean meal; tobacco powder, wheat flour, sawdust, etc.),mineral powders (e.g. clays such as kaolin, bentonite, terra alba, talcssuch as talcum powder and agalmotalite powder, and silicas such asdiatomaceous earth and mica powder), alumina, sulfur powder, and activecarbon. These solid carriers may be used individually or in a suitablemixed form or two or more ingredients in a suitable ratio.

The above-mentioned liquid or solid vehicles (or carriers) can be usedindependently or in combination. An amount of the vehicle is in therange of up to 100% by weight of the whole composition.

Suitable surfactants include alkyl benzene sulfonates and alkylnaphthalene sulfonates, sulfated fatty alcohols, amines or acid amides,long chain acid esters of sodium isothionate, esters of sodiumsulfosuccinate, sulfated or sulfonated fatty acid esters, petroleumsulfonates, sulfonated vegetable oils, ditertiary acetylenic glycols,polyoxyethylene derivatives of alkyl arylethers, polyoxyethylenederivatives of alkylphenols (particularly isooctylphenol andnonylphenol) and polycxyethylene derivatives of the mono-higher fattyacid esters of hexitol anhydrides (e.g., sorbitan), polyoxyethyleneallyl phenyl ether formaldehyde condensates, polyoxyethylene phenylphenol ether sulfates, polyoxyethylene aryl ethers, alkoxylated amines,inorganic ammonium salts, such as ammonium sulphate, ammonium nitrateand ammonium phosphates, ammonium salts derived from organic amines suchas primary, secondary and tertiary amines, diamines such as ethylenediamine and piperazine, morpholine, polyamines, alkoxylated amines andamine surfactants. Preferred dispersants are methylcellulose, polyvinylalcohol, sodium lignin sulfonates, polymeric alkyl naphthalenesulfonates, sodium naphthalene sulfonate, and polymethylenebisnaphthalene sulfonate.

Wettable powders are water-dispersible compositions containing theactive ingredients mixture, an inert solid extender and one or morewetting and dispersing agents. The inert solid extenders are usually ofmineral origin such as the natural clays, diatomaceous earth andsynthetic minerals derived from silica and the like. Examples of suchextenders include kaolinites, attapulgite clay and synthetic magnesiumsilicate. The wettable powders compositions of this invention usuallycontain from above 0.5 to 60 parts (preferably 5 to 20 parts) of activeingredients mixture, from about 0.25 to 25 parts (preferably 1 to 15parts) of wetting agent, from about 0.25 to about 25 parts (preferably 1to 15 parts) of dispersant and from 5 to about 95 parts (preferably 5 to50 parts) of inert solid extender, all parts being by weight of thetotal composition. Where required, from about 0.1 to 2.0 parts of thesolid inert extender can be replaced by a corrosion inhibitor oranti-foaming agent or both.

The compositions of the invention may be in the form of waterdispersible granules (WG) comprising the herbicidally-activeconstituents together with surfactants, dispersing agents,disintegrating agents, fillers, diluents and the like.

The compositions may also be formulated as dust concentrates comprisingfrom 0.1 to 60% by weight of the active ingredients in admixture with asuitable extender or diluent; these dusts may be diluted for applicationat concentrations within the range of about 0.1 to about 10% weight.

Compositions which are aqueous suspensions or emulsions may be preparedby stirring a non-aqueous solution of a water insoluble activeingredients mixture and an emulsification agent with water until uniformand then homogenizing to give an emulsion of very finely dividedparticles. The resulting concentrated aqueous suspension ischaracterized by its extremely small particle size so that when dilutedand sprayed, coverage is very uniform. Suitable concentrations of theseformulations contain from about 0.1 to 60%, preferably 5 to 50%, byweight of active ingredients mixture, the upper limit being determinedby the solubility limit of active ingredients in the solvent.

Concentrates are usually solutions of active ingredients mixtures inwater-immiscible, partially water-miscible or water-miscible solventstogether with a surface active agent. Suitable solvents for the activeingredients of this invention include dimethylformamide,dimethylsulfoxide, N-methyl-pyrrolidone, hydrocarbons, amines andwater-immiscible ethers, esters, or ketones. However, other highstrength liquid concentrates may be formulated by dissolving the activeingredient in a solvent then diluting, e.g., with kerosene, to sprayconcentration.

The concentrate compositions herein generally contain about 0.1 to 95parts (preferably 5 to 60 parts) active ingredients mixture, about 0.25to 50 parts (preferably 1 to 25 parts) surface active agent and whererequired about 4 to 94 parts solvent, all parts being by weight based onthe total weight of emulsifiable oil.

The compositions of the invention can also be in the form of granuleswhich are physically stable particulate compositions comprising activeingredient mixtures adhering to or distributed through a basic matrix ofan inert, finely-divided particulate extender. In order to aid leachingof the active ingredient from the particulate, a surface active agentsuch as those listed hereinbefore can be present in the composition.Natural clays, pyrophyllites, illite, and vermiculite are examples ofoperable classes of particulate mineral extenders. The preferredextenders are the porous, absorptive, preformed particules such aspreformed and screened particulate attapulgite or heat expanded,particulate vermiculite and the finely divided clays such as kaolinclays, hydrated attapulgite or bentonitic clays. These extenders aresprayed or blended with the active ingredient to form the herbicidalgranules.

The granular compositions of this invention may contain from about 0.1to 30 parts by weight of active ingredients mixture per 100 parts byweight of clay and 0 to about 5 parts by weight of surface active agentper 100 parts by weight of particulate clay.

The compositions of this invention can also contain other additives forexample, fertilizers, other herbicides, other pesticides, safeners andother additives commonly used in herbicidal formulations, used asadjuvants or in combination with any of the above-described adjuvants.

Suitable surfactants may be found in "Mc. Cutcheon's Detergents andEmulsifiers Annual", Mc Publishing Corp., Ridgewood, N.J. or inequivalent technical documents.

It is generally admitted that, in case of synergism, the effectivenessof the mixture cannot be computed from that of the individualingredients. Synergism is generally defined as the simultaneous actionof two or more compounds in which the total response of an organism tothe pesticide combination is greater that the sum of the individualcomponents.

A simple mathematical method to test the additivity of a pesticidecombination is based on the equation: ##EQU1## in which X and Yrepresent the percentage-of-inhibition of growth by toxicant A and B,respectively. E is the expected percentage-of-inhibition of growth bythe mixture A and B. In order to show synergism, the actual efficacyshould be higher than E.

The compositions of the invention are active against a variety of weedsand are particularly useful for combating weeds which tend to infestcereal crops, for example the weeds which are listed above on page 2 ofthis specification. Other weeds combated by the herbicidal compositionsof the present invention include, for example, the following:

    ______________________________________                                        Amaranthus retroflexus                                                                             (pigweed)                                                Abutilon theophrasti (velvet leaf)                                            Sida spinosa         (prickly sida)                                           Sesbania exaltata    (hemp sesbania)                                          Xanthium pennsylvanicum                                                                            (cockleburr)                                             Bidens spp.          (marigold)                                               Convolvulus arvensis (field bindweed)                                         Papaver rhoeas       (field poppy)                                            Chrysanthemum segetum                                                                              (corn marigold)                                          Digitaria sanguinalis                                                                              (crabgrass)                                              Setaria faberii      (giant foxtail)                                          Solanum nigrum       (black nightshade)                                       Cyperus esculentus   (edible cyperus)                                         Echinochloa crus-galli                                                                             (barnyard grass)                                         Avena fatua          (wild oat)                                               Avena sterilis       (animated oat)                                           Lolium multiflorum   (rye grass)                                              Agropyron repens     (quack grass)                                            Plantago major       (greater plantain)                                       Cyodon cactylon      (bermuda grass)                                          Spergula arvensis    (corn spurrey)                                           Sinapsis arvensis    (wild mustard)                                           Ipomea purpurea      (morning glory)                                          Chenopodium albium   (fat hen)                                                Ranunculus avensis   (corn butter cup)                                        Rubus fructicosus    (blackberry)                                             Portulaca oleracea   (purslane)                                               Polygonum convolvulus                                                                              (wild buckwheat)                                         Brassica synapsis    (yellow charlock)                                        Achillia milleflorum (yarrow)                                                 ______________________________________                                    

Other species of weeds which are combated, variously, by thecompositions of the present invention, depending upon the chosensulfonylurea and the particular co-herbicide(s) combination include thefollowing: Senecio, Vicia, Ambrosia, Anthemis, Sorghum, Aristolochia,Agrostis, Bromus, Tussilago, Carsium, Viola, Atriplex, Apera, Poa,Capsella, Galinsoga, Datura, Euphorbia, Taraxacum, Plantago, Cynodon,Rumex, and Oxalis.

The invention is illustrated by the following Examples.

EXAMPLE 1

Two sulfonylurea compounds A and B having the structural formulae shownbelow: ##STR4## are formulated as suspension concentrates (SC)containing about 42% by weight of active ingredient.

The compounds were tested alone and in admixture with a co-herbicide,which was also tested alone, against the following weeds:

    ______________________________________                                        Weed                     Designation                                          ______________________________________                                        Alopecurus myosuroides (black grass)                                                                   ALOMY                                                Avena fatua (wild oats)  AVENA                                                Galium aparine (bedstraw cleavers)                                                                     GALAP                                                Lamium purpureum (red dead nettle)                                                                     LAMPU                                                Matricaria chamomilla (mayweed)                                                                        MATCH                                                Stellaria media (common chickweed)                                                                     STEME                                                Veronica persica (common field speedwell)                                                              VERPE                                                ______________________________________                                    

In the test procedure three replicate pots per treatment were randomlyarranged through a growth room. The plants were treated about threeweeks after planting and then submitted to a photoperiod of 14 hours perday; the temperature was 15 degrees Centigrade during the day and 9degrees at night. All applications of test formulations were performedusing a MARDRIVE sprayer, simulating as far as possible fieldconditions. The pressure was controlled at 2 bar and the water volumewas 300 l/ha. The weed plants were at a true leaf stage between 0 to 6leaves.

Assessment of phytotoxicity was made by comparison with untreatedcontrol pots on an arbitrary scale from 0 to 100%, where 0 represents novisible effect and 100 represents a kill of all plants. The results inthe tables and figures are presented as average values of threereplicates.

The co-herbicides tested were, variously, isoproturon (IPU) (ureaherbicide), imazamethabenz-methyl (imidazolinone herbicide), bifenox(diphenyl ether herbicide), bromoxynil (hydroxybenzonitrile herbicide),triallate (carbamate herbicide), difenzoquat (quaternary ammonium salt),flupoxam (triazole herbicide), MCPP (phytohormone herbicide),pendimethalin (2,6-dinitroaniline herbicide), fluroxypyr (phytohormoneherbicide), fenoxaprop-P-ethyl (2-(4-aryloxyphenoxy) alkanoic acidherbicide), isoxaben (amide herbicide) and diflufenican (anilideherbicide). Fenoxaprop-P-ethyl has been used as the commercial productPUMA® which contains a safener. The safener is believed to reduce theinjury to wheat caused by fenoxaprop-P-ethyl in order to render samecommercially more vialable in the competitive environment.

The results of the tests are presented in Table I below.

The results of the tests demonstrate the synergistic effects possessedby the compositions of the invention. Turning again tofenoxaprop-P-ethyl, it should be noticed that the activity on the weedshas been synergized while maintaining the safety of thefenoxaprop-P-ethyl/safener combination to the crop. In practice, thiscould lead to a reduced use of safener.

                                      TABLE I                                     __________________________________________________________________________    Synergy between Sulfonylurea Compounds A and B and various Co-herbicides           Rate (g/ha.)                                                             Weed SU + X                                                                              SU - A                                                                            X Ex   Obs                                                                              SU - B                                                                            X Ex   Obs                                       __________________________________________________________________________    Isoproturon                                                                   ALOMY                                                                              20 + 1000                                                                            0   0                                                                               0   80 10   0                                                                              10   70                                        AVEFA                                                                              30 + 1000                                                                            0   0                                                                               0   40  0   0                                                                               0   10                                        GALAP                                                                              20 + 500                                                                            60   0                                                                              60   90 80   0                                                                              80   95                                        LAMPU                                                                              20 + 500                                                                             0  25                                                                              25   30  0  25                                                                              25   40                                        STEME                                                                              20 + 500                                                                            60   0                                                                              60   90 20   0                                                                              20   80                                        VERPE                                                                              20 + 500                                                                            70   0                                                                              70   85 50   0                                                                              50   80                                        Imazamethabenz                                                                ALOMY                                                                              10 + 300                                                                            10  15                                                                                23.50                                                                            85 10  15                                                                                23.50                                                                            70                                        AVEFA                                                                              20 + 100                                                                            10  30                                                                              37   60  0  30                                                                              30   55                                        LAMPU                                                                              10 + 300                                                                            70  60                                                                              88   97 --  --                                                                              --   --                                        MATCH                                                                              20 + 300                                                                            90   5                                                                                90.50                                                                            97 60   5                                                                              62   95                                        STEME                                                                              10 + 100                                                                            70  10                                                                              73   90 50  10                                                                              55   60                                        VERPE                                                                              10 + 300                                                                            30  10                                                                              37   95 85  10                                                                                86.50                                                                            95                                        VERPE                                                                              20 + 200                                                                            50   0                                                                              50   90 --  --                                                                              --   --                                        Difenzoquat                                                                   ALOMY                                                                              30 + 600                                                                            25   5                                                                                28.5                                                                             80 --  --                                                                              --   --                                        AVEFA                                                                              10 + 600                                                                             0  60                                                                              60   75 --  --                                                                              --   --                                        LAMPU                                                                              10 + 600                                                                            30   5                                                                                33.50                                                                            90 --  --                                                                              --   --                                        STEME                                                                              10 + 400                                                                            50   0                                                                              50   95 --  --                                                                              --   --                                        VERPE                                                                              20 + 200                                                                            50   0                                                                              50   90 --  --                                                                              --   --                                        Triallate                                                                     ALOMY                                                                              10 + 1500                                                                           10  50                                                                              55   80 25  50                                                                                62.50                                                                            80                                        AVEFA                                                                              20 + 1500                                                                           15  65                                                                                70.25                                                                            75  5  65                                                                                66.75                                        LAMPU                                                                              20 + 1500                                                                           --  --                                                                              --   -- 20  50                                                                              60   85                                        MATCH                                                                              20 + 1500                                                                           45  10                                                                                50.50                                                                            80 --  --                                                                              --   --                                        STEME                                                                              30 + 1000                                                                           65  10                                                                                68.50                                                                            75 --  --                                                                              --   --                                        VERPE                                                                              20 + 500                                                                            --  --                                                                              --   -- 50  40                                                                              70   80                                        Difenzoquat                                                                   ALOMY                                                                              30 + 600                                                                            25   5                                                                                28.5                                                                             80 --  --                                                                              --   --                                        AVEFA                                                                              10 + 600                                                                             0  60                                                                              60   75 --  --                                                                              --   --                                        LAMPU                                                                              10 + 600                                                                            30   5                                                                                33.50                                                                            90 --  --                                                                              --   --                                        STEME                                                                              10 + 400                                                                            50   0                                                                              50   95 --  --                                                                              --   --                                        VERPE                                                                              20 + 200                                                                            50   0                                                                              50   90 --  --                                                                              --   --                                        MCPP                                                                          ALOMY                                                                              10 + 1000                                                                            0   0                                                                               0   60  0   0                                                                               0   65                                        AVEFA                                                                              20 + 1000                                                                            0   0                                                                               0   20  0   0                                                                               0   10                                        MATCH                                                                              10 + 250                                                                            70  30                                                                              79   95 70  30                                                                              79   90                                        STEME                                                                              10 + 250                                                                            50  85                                                                                92.50                                                                            100                                                                               0  85                                                                              85   99                                        Pendimethalin                                                                 ALOMY                                                                              30 + 800                                                                            10  10                                                                              19   65 20  10                                                                              28   75                                        AVEFA                                                                              30 + 1200                                                                            0   0                                                                               0   70  0   0                                                                               0   60                                        GALAP                                                                              10 + 1200                                                                           60  60                                                                              84   90 70  60                                                                              88   95                                        LAMPU                                                                              10 + 400                                                                             0  70                                                                              70   80  0  70                                                                              70   80                                        MATCH                                                                              30 + 800                                                                            70  50                                                                              85   97 90  50                                                                              95   97                                        STEME                                                                              30 + 800                                                                            55   0                                                                              55   95 30   0                                                                              30   90                                        VERPE                                                                              20 + 1200                                                                           70  90                                                                              97   99 50  90                                                                              95   99                                        Fluroxypyr                                                                    ALOMY                                                                              30 + 100                                                                            20   0                                                                              20   75 40   0                                                                              40   70                                        AVEFA                                                                              30 + 100                                                                            10   0                                                                              10   65  0   0                                                                               0   10                                        GALAP                                                                              10 + 50                                                                             20  70                                                                              76   90  0  70                                                                              70   95                                        LAMPU                                                                              20 + 1000                                                                           30  50                                                                              65   85 10  50                                                                              55   75                                        MATCH                                                                              10 + 100                                                                            40  20                                                                              52   99 10  20                                                                              28   50                                        STEME                                                                              10 + 100                                                                            --  --                                                                              --   --  0  60                                                                              60   80                                        VERPE                                                                              10 + 100                                                                            20  85                                                                              88   95 10  85                                                                                86.50                                                                            99                                        Flupoxam                                                                      ALOMY                                                                              20 + 100                                                                            --  --                                                                              30   60 --  --                                                                              --   --                                        AVEFA                                                                              20 + 100                                                                            --  --                                                                              10   30 --  --                                                                               0   10                                        Bifenox                                                                       ALOMY                                                                              10 + 500                                                                            --  --                                                                              20   35 --  --                                                                              25   35                                        AVEFA                                                                              30 + 1000                                                                           --  --                                                                              28   55 --  --                                                                              10   25                                        Bromoxynil                                                                    ALOMY                                                                              30 + 1000                                                                           --  --                                                                              30   40 --  --                                                                              40   50                                        AVEFA                                                                              30 + 1000                                                                           --  --                                                                              10   35 --  --                                                                               0   20                                        Fenoxaprop-P-ethyl                                                            ALOMY                                                                              30 + 60                                                                             --  --                                                                              55   75 --  --                                                                              65   90                                        AVEFA                                                                              30 + 30                                                                             --  --                                                                                19.25                                                                            45 --  --                                                                                 9.80                                                                            20                                        Isoxaben                                                                      ALOMY                                                                              10 + 60                                                                             --  --                                                                              35   55 --  --                                                                              45   60                                        AVEFA                                                                              30 + 60                                                                             --  --                                                                              30   45 --  --                                                                              20   30                                        Diflufenican                                                                  ALOMY                                                                              10 + 150                                                                            --  --                                                                              19   30 --  --                                                                                32.50                                                                            40                                        AVEFA                                                                              30 + 150                                                                            --  --                                                                                28.75                                                                            35 --  --                                                                                14.50                                                                            20                                        __________________________________________________________________________

Key to Table I

IPU=Isoproturon

SU=Sulfonylurea

Key to Table I (continued)

SU--A=Sulfonylurea Compound AIPU=Isoproturon

SU--B=Sulfonylurea Compound B

Ex=Expected

Obs=Observed

X=coherbicide as specified at the top of each individual table

What is claimed is:
 1. A herbicidal composition comprising asulfonylurea derivative of formula ##STR5## wherein Q is --CH═CH-- or--S--, R is straight or branched C1-3 alkyl, and X is --OCH₃ or --CH₃,or an agriculturally acceptable salt thereof, and at least oneco-herbicide from the following herbicides:isoproturon, a ureaherbicide, imazamethabenz-methyl, an imidazolinone, bifenox, a diphenylether herbicide, bromoxynil, a hydroxybenzonitrile herbicide,fenoxaprop-P-ethyl, a 2-(4-aryloxyphenoxy) alkanoic acid herbicide,tri-allate, a carbamate/thiocarbamate herbicide, difenzoquatmetilsulfate, a quaternary ammonium salt herbicide, MCPP and fluroxpyr,phytohormone herbicides, pendimethalin, a 2,6-dinitroaniline herbicide,isoxaben, an amide herbicide, diflufenican, an anilide herbicide; therespective herbicidal constituents being present in amounts whereby thecompositions display selectivity of herbicidal action with respect tocrops being treated pre- or post-emergent and exhibit synergisticeffects when applied at herbicidally effective rates.
 2. A herbicidalcomposition according to claim 1 wherein the agriculturally acceptablesalt is a salt formed with an inorganic base selected from the groupconsisting of alkali metals, alkali earth metals, ammonia, and organicbases selected from the group consisting of dimethylamine,triethylamine, pyrrolidine, piperidine, piperazine, morpholine,benzylamine, ethanolamine, and diethanolamine.
 3. A herbicidalcomposition as claimed in claim 1 or claim 2 wherein the sulphonylureais a compound of formula: ##STR6##
 4. A herbicidal composition accordingto claim 1 wherein --R is --C2H5, --X is --OCH3 and Q is --CH═CH--.
 5. Aherbicidal composition according to claim 1 wherein the ratio by weightof the sulfonylurea herbicide to the co-herbicide is from about 1:1 toabout 1:150 and the amounts applied are in the ratio of from about 10:30g/ha to about 25:1500 g/ha.
 6. A method of controlling the germinationand growth of undesired vegetation in a selective manner with regard tocrops being treated, which comprises applying to the crops, pre- orpost-emergent, a composition as claimed in any one of claims 1, 2, 4 or5.
 7. A process for selectively controlling the growth or germination ofundesired plants comprising applying sequentially or simultaneously,pre- or post-emergent to the plants, to the seeds thereof, or to thelocus of the seed or plants or seeds, the herbicidally activeconstituents of a composition as claimed in any one of claims 1, 2, 4 or5.